[1] Okayama Univ, Dept Gastroenterol & Hepatol, Sch Grad Med Dent & Pharmaceut Sci, Okayama 7008558, Japan
[2] Natl Hosp Org, Dept Gastroenterol, Iwakuni Clin Ctr, Iwakuni, Japan
[3] Tsuyama Cent Hosp, Dept Internal Med, Tsuyama, Japan
[4] Kagawa Prefectural Cent Hosp, Dept Internal Med, Takamatsu, Kagawa, Japan
[5] Mitoyo Gen Hosp, Dept Internal Med, Kanonji, Japan